Traction system for treatment of lower limb deformities



Dec. 2, 1969 J. w; CARR TRACTION SYSTEM FOR TREATMENT OF LOWER LIMB DEFORMI'IIES Filed July 5, 1967 2 Sheets-Sheet 1 INVENTOR. C/OHN CAQQ Dec. 2, 1969 J. w. CARR TRACTION SYSTEM FOR TREATMENT OF LOWER LIMB DEFORMITIES Filed July 5, 196'? 2 SheetsSheet 2 INVENTOR (JOHN W CA 22 United States Patent 3,481,331 TRACTION SYSTEM FOR TREATMENT OF LOWER LIMB DEFORMITIES John William Carr, 168 Cronin Drive, Santa Clara, Calif. 95051 Filed July 3, 1967, Ser. No. 658,582 Int. Cl. A61f 5/00; A61h 1/02 US. Cl. 128-80 6 Claims ABSTRACT OF THE DISCLOSURE This invention is a therapeutic device for the treatment of lower limb deformities. Although some deformities treatable by this device may have been caused by a disease, for example, poliomyelitis, its most common use is intended to be for the treatment of congenital club foot also known as talipes. As will be pointed out, certain modifications are made to provide for treatment of talipes valgus and abduction deformities. The pictorial presentations are specific for the treatment of talipes equinovarus, which is inclusive of the treatment for talipes equinus and talipes varus.

Talipes equinovarus is a common congenital club foot deformity where the forefoot tilts forward and downward and is rotated inward about an axis and roughly parallel to the longitudinal axis of the calcaneous. Sometimes this is accompanied by adduction which is an inward rotation of the forefoot with respect to the heel about an axis approximately perpendicular to the longitudinal axis of the calcaneous and parallel to the longitudinal axis of the tibia. The following counter torques are therefore required for the mechanical treatment of these deformities.

For the equinus condition (downward tilt of the forefoot accompanied by a shortening of the Achilles tendon) dorsiflexion of the foot about the ankle joint is required to lengthen the Achilles tendon.

For the varus condition (inward rotation about an axis parallel to the longitudinal axis of the calcaneous) a valgus deflection or outward corrective rotational torque about this axis is required.

For the valgus condition (outward rotation of the foot about an axis parallel to the longitudinal axis of the calcaneous) a varus deflection or inward corrective rotational torque about this axis is required.

For the adduction condition (inward rotation of the forefoot with respect to the heel about an axis paralleling the longitudinal axis of the tibia), an abductive (outer rotational) counter torque about the same axis is required.

For the abduction condition (outward rotation of the forefoot with respect to the heel about an axis parallel to the longitudinal axis of the tibia) an adductive (inner rotational) counter torque about the same axis is required.

These are the corrections that must be applied as seen purely from static mechanical considerations.

There are three other important considerations (regarding the patient per se) however, that are often (necessarily) overlooked.

The first is the dynamic considerations relative to the patient. Everyone is quite aware of the extreme discomfort resulting from the holding of a limb (even a normal limb in the absence of any applied restrictive forces) in Patented Dec. 2, 1969 one position for long periods of time such as hours, days, or Weeks. In a static type of brace or cast this continued restriction of the limb to one position, particularly during sleeping hours or other mentally and physically inactive periods, is very difiicult for the patent to endure.

The second consideration, particularly applicable to full leg bracing and casting techniques, it that, once the correction is made, the muscles and tendons of the foot and leg, having been inactive for long periods, become weakened and may not be capable of holding the correction once it has been attained. In addition, muscular atrophy may result.

The third consideration is the psychological effects on the patient who, in the case of club feet, is usually an otherwise physically and mentally normal child. After attaining a few years of age a child is particularly conscious of his appearance among his peers.

It is the nature of young children to stare at, chide, or otherwise single out a physically handicapped person, particularly one of their own age group.

The device described herein performs the necessary mechanical therapeutic functions. This is done in an easily self-applied intermittent dynamic way so that:

(l) The treatment is more easily endured, not only because the patient can change the position of his feet while he is undergoing treatment, but he may simply get out of the device when necessary.

(2) While in the device and working his feet against the corrective dorsiflexion torque he uses his foot and leg muscles very effectively which, together with the periods he is out of the device, contributes to the development of these important muscles.

(3) Since the treatment can be taken in the privacy of his home and he is free of any fixed attached braces or casts, his psychological reactions are greatly improved.

Thus, with this introduction understood, we proceed now to the description of a particular embodiment of the invention which is easily understood by one who has some familiarity with elementary mechanics. This specific embodiment does not detract from the general nature of the invention. It will be well understood by one experienced in the art that other shapes of the unit and variations in the mechanics of applying corrective torques to the feet are readily apparent.

DESCRIPTION OF FIGURES FIG. 1 is a perspective view (partially in phantom for clarity) of my new system.

FIG. 2 is an enlarged fragmentary view of a portion of FIG. 1 taken along lines 2-2 thereof and broken away for clarity.

FIG. 3 is an enlarged fragmentary view of a portion of FIG. 1 taken along lines 33 thereof and partially broken away for clarity.

In FIG. 1, part 1 is the base for the unit which, in the version shown here, is a seat. Parts 2 and 3 are leaves hinged together by hinges 4 with part 2 serving as a backrest and part 3 as a sliding leaf adjustably connected to base 1 by clamps 8. Part 5 is a stiff linear member pinned at its ends into adaptors 6 and 7, which are attached respectively to leaves 2 and 3, the multiplicity of holes in each of which allow for adjustment of the angle of inclination that back rest 2 makes with base 1. Part 9 is a rigid flap or leaf rotationally connected to one end of base 1 by means of hinges 10. Attached to flap 9 are torque adjusting members 11, each containing a multiplicity of holes for adjustable connection of flap 9 to one end each of inner spring guide tubes 13. Right and left extension springs 12 (seen in the cross section view of FIG. 2) each has one end secured to its respective right or left torque adjusting member 11, and to its respective right or left spring guide tube 13. The other end of each right and left spring 12 is attached to base 1 at one of the holes in respective right or left guide bars 15. The lower ends of right and left spring guide tubes 13 and the lower ends of the respective right or left extension springs 12 are enclosed within respective right or left outer spring guide tubes 14. The lower ends of right and left guide tubes 14 are connected to respective right or left guide bars 15 and to respective lower ends of right or left springs 12. Thus it can be seen that a balanced spring derived force provides a torque on rigid flap 9 in a direction towards the back rest 2. This torque can be adjusted, for a given spring length and stiffness, by choice of attachment holes in torque adjusting members 11 and guide bars 15. Bars 15 also serve as tracks or guides for the back rest sliding leaf 3. Parts 16 are respectively right and left torque angle limiting devices. They are adjustably connected respectively to inner right or left spring guides 13 by set screws so that they provide a minimum limit on the angle of inclination that flap 9 makes with base 1. This angle limit is continuously adjustable.

Foot pad 17 consists of right and left rigid wings or leaves 18 rotationally connected to each other by means of hinges 19 and are attached to flap 9 by means of screws 19a shown with washers under their heads and inserted in the gap between wings 18 (along the line of the axis of and between hinges 19) and into part 20. Part 20 is a spacer running the full length of the foot pad wings 18 and is attached to flap 9 along its vertical center line. See FIG. 3 for better detail. Parts 21 and 21a (a right and left of each) are L brackets attached respectively to the right or left sides of flap 9 and the right or left sides of foot pad wings 18. The brackets 21 have a multiplicity of holes to provide for adjustment of the inclination angle of the foot pad wings 18 with respect to the surface of flap 9. Numbers indicating corresponding angles of inclination are placed alongside of each hole. FIG. 3 shows a top View of the foot end of the apparatus which more clearly defines the functions of parts 18 through 21a. Cushion 22, indicated by a dashed line, covers the exposed face of the wings 18 upon which the feet of a patient are placed. Right and left spreader bars 23 ride on top of cushion 22 and are pivoted respectively about right or left pivot bolts 24 which are attached respectively to the lower sides of right or left wings 18. These spreader bars and the connections to spring guide tubes 13 are purposely left off the drawing of FIG. 3 in order to provide more clarity in showing the other parts. The top sides of right and left wings 18 are each out along a radius of curvature with respective right or left pivot bolt 24 as a center. Right and left clamps 25 provide angularly adjustable spreader bar attachment respectively to right or left foot pad wings 18. Calibration marks along the upper radiused edges of wings 18, shown in FIG. 3, indicate their angle of inclination. Dashed lines in FIG. 1 show the seat and back cushions 26 and 27 respectively. Cushion 26 pads the buttocks, backs of the thighs and calves, and serves to keep the heels of a patient sufiiciently above base 1 when he places his feet against foot cushion 22 so that there is no abrasion of the backs of the heels. Cushion 27 is a back cushion for increased comfort of the patient. Legs or castors may be attached to the bottom side of base 1. It is recommended that spreader bars 23 be upholstered on the side next to the foot. Protractor 28 shows the inclination angle of flap 9, and thus the padded faces of foot pads 18, with respect to base 1.

The operation of the complete unit is now quite clear. The patient seats himself on cushion 26 with legs straight ahead of him resting on cushion 26 and with his back against cushion 27. Another person now adjusts sliding leaf 3 of the back rest attachment until the bottom of the patients feet fit snugly against cushion 22 of the winged foot pad 17, outside of spreader bars 23, then tightens clamps 8 sothat this position of sliding leaf 3 is maintained. Next he adjusts the angle of inclination of backrest leaf 2 by adjustment of the position of the at- 4 tachment of the ends of member 5 to members 6 and 7. The patient will generally help determine which adjustment is most comfortable for him. The angles of inclination of the wings 18 of foot pad 17 are adjusted to the prescribed valgus angle by placing the bolt that connects bracket 21 to 21a through the hole in 21 that is beside the calibration number indicating the inclination angle in degrees. If there is only an equinus deformity the inclination angle of wings 18 will generally be prescribed to be a small angle or zero degrees. Note that the right and left wings are independently adjustable. Similarly the prescribed angular separation of spreader bars 23 is made by adjusting clamps 25. These adjustments are also independent of each other. The dorsiflexion torque is controlled by the amount of deflection of extension spring 12 (determined by the point of attachment to guide bar 15 and by the choice of point of attachment to part 11). Torque angle limiters 16 set limits on maximum dorsiflexion angle independent of the torque. The amount of abduction on each foot is controlled by each spreader bar inclination angle along with the valgus angle and the dorsiflexion torque and angle. The abduction torque derived is increased as the spreader bar angle with the vertical is increased and as valgus tilt and dorsiflexion torque angle is increased and is thus not independent of these torques nor of the friction between the soles of the feet and the cushion 22. The patient is free to work his feet against the dorsiflexion torque to relieve the monotony of a fixed position and in so doing he provides excellent exercise for his calf and foot muscles. All he has to do to detach himself (he really isnt attached) is simply to raise his knees till angle limiters 16 stop against the upper edges of tubes 14 and then arise. Limiters 16 are adjusted to a prescribed limiting inclination angle of flap 9 with respect to base 1 as indicated by the calibration on protractor 28. Once the proper adjustments have been made the patient gets in and out of the seat with ease and there are no further requirements for another person to make adjustments until further prescription changes or obvious need for such changes arises.

For correction of valgus and abduction deformities part 20 (the spacer under foot pad 17) is made so that it extends much further out from the inside surface of flap 9 The bolts connecting parts 21 and 21a are put in holes closer to the base of brackets 21 (which now have negative inclination angles calibrated thereon) and wings 18 are radiused on the bottom edges instead of the top. Spreader bars 23 are separated far enough so that the patients feet are placed on the inside of them and their angle of tilt is inward toward the top. The reversed angular tilt of wings 18 and the spreader bars now provides varus and adduction inclination (corrective therapy for valgus and abduction deformities).

Now that the principles of operation have been explained it is obvious to anyone skilled in the art that various forms and devices may be implemented to accomplish the same results but still be within the spirit and scope of this invention.

For a few examples of other variations of the basic elements of this invention the following are listed:

A standing vertical or slightly inclined from vertical position of the base 1 may be used, without leaves 2 and 3, so that a patient may stand in the device using his body weight to force the feet into the corrective positions. Also the base 1 may be made longer and provisions made for the shoulders or hips to push against some restricting device such as a waist belt operatively attached to base 1 or alternately with shoulder stops on both sides of the neck and operatively attached to base 1 so that the therapy could be administered to a patient in a prone position lying on his back.

Torsion springs mounted alongside of or in lieu of the hinges 10 can be used to apply torque to flap 9. Also a torsion bar could be mounted on the axis of rotation of the flap 9 to provide torque.

A vertical member supporting a sheave in an elevated position above base 1 can be mounted on each side of base 1 so that the sheave rotates about a horizontal axis transverse to the seat. Ropes attached to the holes in torque adjusting members 11, one on each side, passing over a corresponding right or left side sheave to suspended weights can thereby provide weight controlled dorsiflexion torque.

Pneumatic, hydraulic, or electro mechanical devices could be used to provide the dorsiflexion torque. Motor driven intermittent torques can be supplied this way.

Calibration numbers placed on the inner spring guides 13 using the coincidence of these numbers with the upper edges of outer spring guides 14 provide an indication of spring tension applied to the torque adjusting members 11. Numbers beside the holes in 11 indicated the distance in inches from the axis of the hinges 10. Since the center lines of the extension springs 12 are approximately normal to the surface of flap 9, a simple arithmetical multiplication of these numbers (one set for each side) gives the amount of torque applied to flap 9 and thence to foot pad 17. This is not the dorsiflexion torque, however. The dorsiflexion torque is the sum of the torques integrated along the foot from the heel to toe (of a patient using the device) about the patients ankle joint. Forces on the bottom of the heel back of the ankle joint provide a negative or anti-dorsiflexion moment. The forces forward of the ankle joint provide a larger positive dorsiflexion moment so that the effective torque is positive. Consequently the torque applied to flap 9 about the axis of hinges is only a relative indication of net positive dorsiflexion torque about the ankle joint of the patient. As previously pointed out the protractor 28 mounted on one of the front corners of base 1, using the front or back edge of flap 9 as an indicator, provides a quantitative measurement of dorsiflexion angle.

It is obvious that either right or left wing 18 of foot pad 17 can be mounted and hinged separately or by itself to spacer 20 on flap 9 such that corrective treatment can be given to either foot alone. However, this can be done by merely having the patient raise one knee such that only one foot has torque applied to it.

It will be noted that the dorsiflexion torque is the prime torque. All other torques are derived as required, directly or indirectly, from the prime dorsiflexion torque.

I claim as my invention:

1. An apparatus for the treatment of lower limbs comprising a padded base, having first and second ends, operationally inclined to lie in or approximately in a horizontal plane, a padded back rest translationally adjustably connected to said base between said first and second ends, said back rest fully adjustable in elevation angle from approximately zero degrees to approximately ninety degrees from said base, a rigid foot support flap operationally connected to said base in the vicinity of the second of said ends of said base and operationally extending in a generally vertical direction, operationally variable, from said base, a bilateral foot pad consisting of a right and left leaf operationally connected to the side of said foot support flap that faces said back rest, said right and left foot pad leaves adjustably angularly inclined with the side of said foot support that faces said back rest, a set of two angular spreader bars, a right and a left, angularly adjustble, attached respectively to said right and left foot pad leaves such that they are angularly adjustable with respect to each other and such that they face in the direction of said back rest, force means operationally connected to said base and said foot support flap, with said base, said back rest, said foot support flap, said foot pads, said spreader bars, and said force means operationally coordi nating so that when a patient reclines on said base and said back rest with his legs extending in front of his trunk, straight from buttocks to feet, the bottoms of his feet will rest against said foot pads, the forepart of each respective right foot or left foot of said patient angularly positioned and restricted by each respective right or left spreader bars in cooperation with each respective right or left foot pad, each of said spreader bars cooperating with said foot support at an adjustable small acute angle so that when said force means is applied to said foot support to produce a torque angularly towards said back rest a dorsiflexion torque, and, depending upon the angular adjustment of said right and left foot pad leaves and said respective right and left spreader bars, a valgus or varus torque and an abductive or adductive torque is applied to one foot or both feet of a patient when a patient is using said apparatus for lower limb treatment.

2. An apparatus for the treatment of lower limbs as set forth in claim 1 wherein spring means constitute said force means.

3. An apparatus for the treatment of lower limbs as set forth in claim 1 wherein weight means constitute said force means.

4. An apparatus for the treatment of lower limbs as set forth in claim 1 wherein electromechanical means constitute said force means.

5. An apparatus for the treatment of lower limbs as set forth in claim 1 wherein hydrodynamic means constitute said force means.

6. An apparatus for the treatment of lower limbs as set forth in claim 1 wherein pneumatic means constitute said force means.

References Cited UNITED STATES PATENTS 2/ 1944 Johanson 27258 2/ 1962 Malone et al. 27257 US. Cl. X.R. 12825; 27258 

